Batch request to /@registry fails with json serilazation issue

[Sakoes]

When sending requests to the /@registry endpoint to retrieve registry options. The request fails when there is a json serialization issue in only one of the registry options.

$ curl http://localhost:6003/Plone/@registry\?b_size\=3226 -H "Accept: application/json" --user admin:admin

{
  "message": "Object of type datetime is not JSON serializable",
  "traceback": [
    "File \"/buildout/eggs/Zope-5.7-py3.8.egg/ZPublisher/WSGIPublisher.py\", line 167, in transaction_pubevents",
    "    yield",
    "",
    "  File \"/buildout/eggs/Zope-5.7-py3.8.egg/ZPublisher/WSGIPublisher.py\", line 376, in publish_module",
    "    response = _publish(request, new_mod_info)",
    "",
    "  File \"/buildout/eggs/Zope-5.7-py3.8.egg/ZPublisher/WSGIPublisher.py\", line 271, in publish",
    "    result = mapply(obj,",
    "",
    "  File \"/buildout/eggs/Zope-5.7-py3.8.egg/ZPublisher/mapply.py\", line 85, in mapply",
    "    return debug(object, args, context)",
    "",
    "  File \"/buildout/eggs/Zope-5.7-py3.8.egg/ZPublisher/WSGIPublisher.py\", line 68, in call_object",
    "    return obj(*args)",
    "",
    "  File \"/buildout/eggs/plone.rest-2.0.0-py3.8.egg/plone/rest/service.py\", line 22, in __call__",
    "    return self.render()",
    "",
    "  File \"/buildout/eggs/plone.restapi-8.32.6-py3.8.egg/plone/restapi/services/__init__.py\", line 22, in render",
    "    return json.dumps(",
    "",
    "  File \"/usr/lib64/python3.8/json/__init__.py\", line 234, in dumps",
    "    return cls(",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 201, in encode",
    "    chunks = list(chunks)",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 431, in _iterencode",
    "    yield from _iterencode_dict(o, _current_indent_level)",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 405, in _iterencode_dict",
    "    yield from chunks",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 325, in _iterencode_list",
    "    yield from chunks",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 405, in _iterencode_dict",
    "    yield from chunks",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 405, in _iterencode_dict",
    "    yield from chunks",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 405, in _iterencode_dict",
    "    yield from chunks",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 438, in _iterencode",
    "    o = _default(o)",
    "",
    "  File \"/usr/lib64/python3.8/json/encoder.py\", line 179, in default",
    "    raise TypeError(f'Object of type {o.__class__.__name__} '"
  ],
  "type": "TypeError"
}

[davisagli]

What would you expect to happen instead?